It's hard to dodge sugar because we have no idea about how much added sugar is in the food and drink we consume every day.
That's a key finding of a major review of evidence around sugar consumption and its health impacts, published today by the Royal Society of New Zealand.
Present guidelines from the World Health Organisation (WHO) puts "excessive consumption" at more than 12 teaspoons of added sugar per day for most people - a level too many of us are likely crossing each day.
"It is difficult to know just how much sugar you are consuming," said the society's president, Emeritus Professor Richard Bedford.
"With a typical can of sugar-sweetened fizzy drink containing nine teaspoons of sugar, and sugar added to a wide range of food products in New Zealand, including items we think of as savoury, it is likely that many New Zealanders are exceeding WHO guidelines regularly, if not every day."
WHO guidelines also recommend keeping sugar intake for adults and children to below six teaspoons per day, but these do not apply to sugars found in whole fruits, milk and vegetables.
Food labelling in New Zealand does not allow consumers to assess how much sugar has been added to food and drink, making it difficult to follow these recommendations.
"The role of sugar in developing obesity is also important given that New Zealand is now ranked third after the US and Mexico for rates of obesity," Bedford said.
In New Zealand, around 31 per cent of adults and 11 per cent of children aged 2 to 14 are considered obese.
While it is just one aspect of our diet and lifestyle, sugar has come under increasing scrutiny as the understanding of how it is used and processed in the body has increased.
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While the society's evidence review re-affirmed many widely known facts around large intakes of sugar - notably effects on weight gain, dental decay and links to metabolic diseases like obesity, type-2 diabetes, heart disease and gout - it also found many areas where more research was urgently needed.
There was research under way to determine whether different sugars have different impacts on health, such as high levels of fat in the blood and increased blood pressure.
"There is still more research to be done to fully establish and confirm the links between sugar consumption and health impacts, but there is a growing weight of evidence that the risks posed by excessive sugar in diets, especially added sugar in sweetened drinks and processed foods, need to be taken seriously."
Particularly, there was growing evidence that fructose - which makes up about half of the refined sugar we use and consume in sweetened food and drinks each day - had a role in several diseases.
University of Auckland researcher Professor Peter Shepherd, who is leading a major fructose study in New Zealand schools, said there was a "huge difference" in the way individuals respond to different sugars, either in the way they absorb them from the gut or the way they later metabolise them.
"I think the research needs to address this as those who are at highest risk need to be made aware of the issues as they relate to them."
The Ministry of Health keeps watch of international developments in research, but continues to inform its food and activity guidelines and advice with WHO recommendations.
"The nutrition advice in the latest guidelines suggest people should eat mostly whole foods and reduce their intake of saturated fats, salt and sugar," said the ministry's public health principal adviser, Harriette Carr.
"Our current advice on sugar is to choose and/or prepare foods and drinks with little or no added sugar."